This invention pertains to a pulverizing mill for particulate materials such as coal, in which the mill rollers are each loaded by loading arms and spring units located external to the mill casing.
Pulverizing mills for coal are well known and the prior art has provided many designs of pulverizing mills using multiple rollers which are pivotally mounted from the mill casing or wall and are spring-loaded so as to press downwardly onto the material such as coal being pulverized. Most such pulverizing mills utilize roller loading arrangements located within the mill casing. However, some recent pulverizer designs have roller loading means located at least partly outside the pulverizer casing. For example, U.S. Pat. No. 4,072,276 to Romanowski; U.S. Pat. No. 4,538,768 to Paskowski et al; U.S. Pat. No. 4,717,082 to Guido et al; U.S. Pat. No. 4,706,900 to Prairie et al; and U.S. Pat. No. 4,759,509 to Prairie disclose pulverizing mills such as for coal, which utilize multiple rollers spring-loaded by coil type springs which are adjustable from outside the pulverizer casing. However, these prior art designs have the disadvantage that the loading arm and spring elements are located within the mill casing where they are exposed to abrasive particles which cause wear. These abrasion problems have now been advantageously overcome by the present invention.